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Publication numberUS3908151 A
Publication typeGrant
Publication dateSep 23, 1975
Filing dateJun 22, 1973
Priority dateJun 22, 1973
Also published asDE2429549A1
Publication numberUS 3908151 A, US 3908151A, US-A-3908151, US3908151 A, US3908151A
InventorsSchermerhorn Jerry D
Original AssigneeOwens Illinois Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method of and system for introducing logic into display/memory gaseous discharge devices by spatial discharge transfer
US 3908151 A
Abstract
A method of introducing logic such as AND, NAND, OR and NOR functions into gaseous discharge display/memory devices having electrodes positioned to define discharge sites within a range of mutual influence so that the transfer of one site to the "on state" of discharge will, in the presence of appropriate potentials applied to the electrodes, cause an adjacent site to be placed in the "on state" of discharge by spatial discharge transfer. A transfer of the spatial discharge transfer related discharge sites to an "off state" of discharge can be accomplished by imposing coincident "turn off" signals on all related sites. Coincidence gating to an "on state" can be accomplished by inverting the matrix of sites of the device from an "off state" to an "on state," imposing coincident "turn off" signals on all spatial discharge transfer related sites, and reinverting the matrix of sites. A system is disclosed for turning sites "off" or "on" to achieve logic functions within the device.
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[ l Sept. 23, 1975 play/memory devices having electrodes positioned to define discharge sites within a range of mutual influence so that the transfer of one site to the on state" of discharge will, in the presence of appropriate potentials applied to the electrodes, cause an adjacent site to be placed in the on state of discharge by spa tial discharge transfer. A transfer of the spatial dis charge transfer related discharge sites to an off state of discharge can be accomplished by imposing coincident turn off signals on all related sites. Coincidence gating to an on state" can be accomplished by inverting the matrix of sites of the device from an off state to an on state, imposing coincident turn off signals on all spatial discharge transfer related sites, and reinverting the matrix of sites, A system is off or on" to achieve The method and system are shown for a unitary logic function and element and for matrix or group of logic functions and elements selectively operated,

37 Claims, 6 Drawing Figures United States Patent Schermerhorn METHOD OF AND SYSTEM FOR INTRODUCING LOGIC INTO DISPLAY/MEMORY GASEOUS DISCHARGE DEVICES BY SPATIAL DISCHARGE TRANSFER Inventor: Jerry D. Schermerhorn, Swanton,

Ohio

Assignee: Owens-Illinois, Inc., Toledo, Ohio Filed: June 22, 1973 Appl. No.: 372,542

U.S. Cl. 315/169 TV; 315/169 R; 340/324 M e k V e d mm St s mFm a T mm m m w r X NW N o C fm dn 4 E u l b G S 1 mm [7/ 4a m n b 1.6 G wvM w n u N $9 M 8 n a W m in flu Q 0 R M. W n t as U 92 S H llll l Y9 H N m m m i un i lr & U E m a M nnlfillHrfi +l G 3 d m D t j N WA m c \fl-+ l G m w m 1| km 5 NH H .n n Wm H dmo 5n: 5 m CTMS RCD R H A l e D H e H VWI T 0 w H wSW JH mh 8 R I a 24 1 He T m C S W n A WNW Mm F d 1 W to B T 34 1. [F 22 .\..I| N wa I ll I 27 m m l 55 U 3 3 FAA US Patent Sept. 23,1975 Sheet 1 of 2 3,908,151

US Patent Sept. 23,1975 Sheet 2 of2 3,908,151

CONTROL 48 6 LOGIC USER SELECT ION LOGIC (DECODI NGJ (CLOCK I NC) INTERFACE 55 SUSTAINER SUSTAINER PULL VUP CKT. PULL VDN. CKT

SUSTAINER SUSTAINER UST INER PULL UP CKT. PULL DN. CKT. PULLTO GROUND DN DN L DN SER PULSER PULSER PULSER IOI I02 I03 PULL UP L L L L U PU L L L PULSER PULSER PULSER PULSER PULSER PULSER #2 #3 #4 fir 5 #5 142 I43 I44 I45 METHOD OF AND SYSTEM FOR INTRODUCING LOGIC INTO DISPLAY/NIEMORY GASEOUS DISCHARGE DEVICES BY SPATIAL DISCHARGE TRANSFER CROSS REFERENCE TO RELATED APPLICATIONS This application is related to the United States Patent Applications of Jerry D. Schcrmerhorn for Spatial Discharge Transfer Gaseous Discharge Display/Memory Panel", Ser. No. 372,730 (Case 8-12404); for Display/Memory Geseous Discharge Panel Interconnections to Driving Circuits, Ser. No. 372,541, new U.S. Pat. No. 3,846,656 (Case S-l25l5)", for Method of Driving and Addressing Gas Discharge Panels by lnversion Techniques, Ser. No. 372,553, now U.S. Pat. No. 3,851,210 (Case S-l2513); and for Circuits for Driving and Addressing Gas Discharge Panels by Inversion Techniques", Ser. No. 372,549, now US. Pat. No. 3,840,779 (Case S-l3030).

BACKGROUND OF THE INVENTION This invention relates to methods of and apparatus for control of gaseous discharge display/memory devices and more particularly to methods of and appara tus for performing logic functions internally of the device.

Heretofore, multiple gas discharge display and/or memory panels have been proposed in the form of a pair of opposed dielectric charge storage members which are backed by electrodes, the electrodes being so formed and oriented with respect to an ionizable gaseous medium as to define a plurality of discrete gas discharge units or cells. The cells have been defined by surrounding or confining physical structure such as the walls of apertures in a perforated glass plate sandwiched between glass surfaces and they have been defined in an open space between glass or other dielectric backed by conductive electrode surfaces by appropriate choices of the gaseous medium, its pressure and the electrode geometry. In either structure, charges (electrons and ions) produced upon ionization of the gas volume of a selected discharge cell, when proper alter nating operating voltages are applied between the opposed electrodes, are collected upon the surface of the dielectric at specifically defined locations and ccmsti tute an electrical field opposing the electrical field which created them so as to reduce the voltage and terminate the discharge for the remainder of the cycle portion of the discharge producing polarity. These collected charges aid an applied voltage of the polarity opposite that which created them so that they aid in the initiation of a discharge by imposing a total voltage sufficient to again initiate a discharge and collection of charges. This repetitive and alternating charge collection and ionization discharge consitutes an electrical memory.

An example of a panel structure containing nonphysieially isolated or open discharge cells is disclosed in U.S. Letters Patent No. 3,499,167 issued to Theodore C. Baker, et al. Physically isolated cells have been disclosed in the article by D. L. Bitzer and H. G. Slottow entitled The Plasma Display Panel A Digitally Addressable Display With Inherent Memory" Proceeding of the Fall Joint Computer Conference, I E E E, San Francisco, California, November, 1966, pp 541-547 and in U.S. Letters Patent No. 3,559,190.

One construction of a memory/display panel includes a continuous volume of ionizable gas confined between a pair of dielectric surfaces backed by conductor arrays, typically in parallel lines with the arrays of lines orthogonally related, to define in the region of registration of electrode areas when viewed along common perpendiculars to the arrays a plurality of opposed pairs of charge storage areas on the surfaces of the dielectric bounding or confining the gas. Many variations of the individual conductor form, the array form, their relationship to each other and to the dielectric and gas are available, hence the orthongonally related, parallel line arrays are discussed herein merely as illustrative.

Another construction as disclosed in United States Patent Application of Jerry D. Schcrmerhorn Ser. No. 239,015 filed Oct. 29, 1972, and entitled Monolithic Display Device comprises a dielectric sheet member having generally parallel major faces separated by a given thickness supporting two conductor arrays. A first conductor array, which can be parallel spaced conductors, is mounted on one major surface of the dielectric member and a cooperating second conductor array is mounted on the opposite surface so that individual conductors in the opposite arrays define cooperating conductor pairs. Cavities are formed in the dielectric member adjacent each cooperating conductor pair and are filled with an ionizable gas to form a portion of the wail of a hermetically sealed discharge site associated with each pair. Advantageously, a thin dielectric overcoat is applied to those conductors otherwise exposed to the hermetically sealed volume so that the conductors are not in direct contact with the ionizable gas.

Generally the multicelled gas discharge display/memory panels have been made of a pair of dielectric films separated by a thin layer or volume of gaseous discharge medium and covering conductor arrays on rigid non-conductive support members such as transparent glass panels. The conductors of the arrays are narrow strips of thin conductive material, typically about 8,000 angstroms thick, and may be of transparent, semitransparent, or opaque material such as tin oxide, gold or aluminum. In typical orthogonal arrays, parallel lines of about 3 mils width spaced 17 mils center to center and having a resistance less than about 1,000 ohms per linear inch of conductor line and usually less than 50 ohms per inch have been employed. Such constructions have been modified to enhance their light output from discharging cells by minimizing the shadow" area of two crossing conductors by having at least one of the conductor arrays, usually that on the viewing side, formed of conductors each made up of conductive bridges in the display area or at the element ends. This arrangement provides multiple element unitary conductors of the panel located so that the discharge is exposed between the elements without the present of an intervening opaque or semiopaque conductive layer over the center of the discharge site. Details of such a divided conductor discharge device construction are shown in U.S. Pat. No. 3,603,836 which issued Sept. 7, 1971 to John D. Grier and is entitled Conductor Configurations for Discharge Panels".

In prior art, a wide variety of gases and gas mixtures have been utilized as the ionizable gaseous medium it being desirable that the gas provide a copious supply of charges during discharge, be inert to the materials with which it came in contact, and where a visual display is desired, be one which produces visible light or radiation which stimulates a phophor. Preferred embodiments of the display panel have utilized at least one rare gas, more preferably at least two, selected from helium, neon, argon, krypton or Xenon.

In an open cell Baker et al. type panel, the gas pressure and the electric field are sufficient to laterally con fine charges generated on discharge within elemental or discrete dielectric areas confined generally to a region in proximity to the registering projections of opposed electrodes through the dielectric layers and gas. The space between the dielectric surfaces occupied by the gas is such as to permit photons generated on discharge in a selected discrete or elemental volume of gas to pass freely through the gas space and strike surface areas of dielectric remote from the selected discrete volumes, such remote, photon struck dielectric surface areas thereby emitting charges particles so as to condition at least one elemental volume other than the elemental volume in which the photons originated.

With respect to the memory function of a given discharge panel, the allowable distance or spacing between the dielectric surfaces depends inter alia, on the frequency of the alternating potential imposed, the distance typically being greater for lower frequencies.

While the prior art does disclose gaseous discharge devices having externally positioned electrodes for initiating a gaseous discharge, sometimes called elec trodeless discharge", such prior art devices utilized frequencies and spacing or discharge volumes and gas pressures such that although discharges are initiated in the gaseous medium, such discharges are ineffective or not utilized for charge generation and storage at higher frequencies. Although charge storage may be realized at lower frequencies, such charge storage has not been utilized in a display/memory device in the manner of the Bitzer-Slottow or Baker et al. devices.

In operation of the display/memory device an alternating voltage is applied, typically, by applying a first periodic voltage wave form to one array and applying a cooperating second wave form, frequently identical to and shifted on the time axis with respect to the first wave form, to the opposed array to impose a voltage across the cells formed by the opposed arrays of electrodes which is the algebraic sum of the first and second wave forms. The cells have a voltage at which a discharge is initiated. That voltage can be derived from externally applied voltage or a combination of wall charge potential and externally applied voltage. Orginarily, the entire cell array is excited by an alternating voltage which, by itself, is of insufficient magnitude to ignite gas discharges in any of the elements. When the walls are appropriately charged, as by means ofa previous discharge, the voltage applied across the element will be augmented, and a new discharge will be ignited. Electrons and ions again flow to the dielectric walls extinguishing the discharge; however, on the following half cycle their resultant wall charges again augment the applied external voltage and cause a discharge in the opposite direction. The sequence of electrical discharges is sustained by an alternating voltage signal that, by itself, could not initiate that sequence. The half amplitude of this sustaining voltage has been disignated V Any given cell has a range of sustaining voltages. A panel is operated near the center of this range to accommodate individual cell differences.

In addition to the sustaining voltage there are manipulating voltages or addressing voltages imposed on the opposed electrodes of a selected cell or cells to alter the state of those cells selectively. One such voltage termed a writing voltage transfers a cell or discharge site from the quiescent to the discharging state by virtue of a total applied voltage across the cell sufficient to make it probable that on subsequent sustaining voltage half cycles the cell will be in the on state. A cell in the on state can be manipulated by an addressing voltage termed an erase voltage which transfers it to the off state by imposing sufficient voltage to draw off the surface or wall charges on the cell walls and cause them to discharge without being collected on the opposite cell walls so that succeeding sustainer voltage transitions are not augmented sufficiently by wall charges to ignite discharges.

A common utilization of writing voltages is to superimpose them on a sustainer wave form in an aiding direction and cumulatively with the sustainer voltage achieve the cells turn on voltage. Erase voltages are superimposed on a sustainer wave form in opposition to the sustainer voltage to develop a voltage level suffcient to draw the charges from the dielectric surfaces and discharge them without collecting charges in a significant quantity on the dielectric wall opposite that from which they were drawn. The wall voltage of a dis charged cell is termed an off state wall voltage and frequcntly in midway between the extreme magnitude limits of the sustainer voltage, 2 V

The stability characteristics and non-linear switching properites of these bistable cells are such that in the case of a cell which has not fired in the preceding half cycle of sustaining voltage the state of any cell in the cell array can be changed by selective application of an external voltage which exceeds the turn on or discharge igniting potential. ln the case of a cell which has been fired in the preceding half cycle and has accumulated charges which can aid the sustaining voltage, the cell can be turned off by applying a voltage which discharges the cell. These manipulating signals are applied in a timed relationship with the alternating sustaining voltage, and through control of discharge intensity, accomplish selective state transitions by changing the wall voltage of only the cell being addressed.

Cells are transferred to the on state by applying a portion of the manipulating signal superimposed on the sustaining voltage termed a "select signal" on each of two opposed electrodes which constitute the cell. Conventionally. like sustaining signals are imposed on each electrode array so that half the sustaining voltage is imposed on each array and half the select signal is imposed on the addressed cell electrode in each electrode array at a time when the sum of the applied voltages is sufficient to ignite a discharge. Further, the partial select signals on each electrode are limited to a value which will not impose a firing potential across other cells defined by that electrode and not selected. A typical write signal for a cell is developed by applying half select voltage to the addressed elc'trodes of the cell to be placed in the on state at a time the sustaining voltages are developing a pedestal potential somewhat below the maximum sustaining voltage. Typically, a write signal is imposed on each opposed electrode of the cell during the terminal portion of a sustain voltage half cycle when any wall charging which may result from the prior sustainer transient is substantially completed. The manipulating signal thus ignites a single, and unique, cell at the intersection of the selected two opposed electrodes. This ignited discharge thus establishes the cell in the on state since a quantity of charge is stored in the cell such that on each succeeding half cycle of the sustaining voltage, a gaseous discharge will be produced.

In order to erase a cell or transfer it to the off state the charge stored in the cell is discharged at a time when the sustaining voltage is imposing a voltage in opposition to the wall charge voltage. As for writing, the erase manipulation is facilitated if the sustaining voltage is at a pedestal level below the level providing the maximum applied voltage so that the erase half select voltages are at a convenient level. Typically an erase signal is imposed on each opposed electrode of the cell during the terminal portion of a sustain voltage half cycle, when the wall charging from the prior sustainer discharge is substantially completed, but proceeding the next half cycle alternation by enough time so that the wall discharge of the selected cell is substantially stabilized.

In order to achieve useful displays, it is frequently necessary to provide a large matrix of cells. One arrangement utilizes a plane panel of 262,144 cells in an orthogonal array formed by 5 l2 parallel, straight conductive bands in each of two dimensions, as a row and column, and thus requiring 1024 controlled inputs. Since both turn on and turn off signals are employed at such inputs the circuits can be extensive. Typically, an interface to equipment such as a computer, or typewriter applies signals to a decoder which translates the signals to cell locations by defining the row and column whose projected intersections, as viewed along the common perpendicular to each array of the panel, define the cell regions. Transfer of the discharge state of a large number of cells is required to achieve meaningful displays. The decoding involves numerous logic functions for each display bit which heretofore have been performed in circuitry external of the display device. In US. Letters Patent No. 3,684,918 issued Aug. l5, 1972 to Larry J. Schmersal for Gas Discharge Display/Memory Penels and Selection and Addressing Circuits Therefore" multiplexing of the signals to the conductors of each panel array has been accomplished with conbinations of diode and resistor pulsers arranged to respond predetermined coincident signals in order to manipulate cell potentials.

An object of the present invention is to improve gas discharge display/memory devices.

Another object is to facilitate the control of manipulation of cell states in gas discharge display/memory devices.

A third object is to simplify the circuitry required to manipulate cell states in gas discharge display/memory devices.

SUMMARY OF THE INVENTION In accordance with the above objects a feature of this invention involves controls for performing logic internally of a gas discharge display/memory device wherein at least two discharge sites are so spaced that the presence of a discharge in one site institutes a discharge in the other. Spatial discharge coupled dischage sites can be considered in combination, to be a cell since by their proximity they produce a single display bit. Accordingly, the individual discharge sites which when grouped for a cell are termed discharge sub sites.

One feature of control of a cell having at least two sub sites is that of an OR wherein the application of a turn on signal on the conductors forming one sub site initiates a discharge in that sub site and, by virtue of the fringing of the wall charge accumulation in that sub site into the region of its associated sub site, initiates a discharge in the associated sub site. In its simplest form a cell of this type can have a single conductor in one conductor array and a pair of conductors in the other array having proximate portions at their cross points with the one conductor so that the one conductor is common to both sub sites. Where two conductors each having proximate portions are present in each array with their proximate portions at their cross points as viewed along the common perpendicular to each array of the panel the cell will comprise four sub sites any one of which when placed on state of dicharge will institute an on state of discharge in the other three.

A coincidence gating function is another feature of this invention. Since the presence of an on state of discharge in any sub site of a cell will place all other sub sites of that cell in an on state of discharge, in order to transfer a cell to an off state of discharge all cells must be so transferred. Thus where the turn off signal superimposed on the sustainer voltage applied across the cell is applied to opposed conductors of the discharge sub site to turn off the sub site, all conductors of all sub sites of the cell must be subjected to turn off signals which are effective in the same half period of the sustainer voltage in order to turn off the cell.

Coincidence or AND gating can be employed to advantage for both turn on and turn off of a cell by applying electronic inversion to the cell. That is, instead of turning the cell on with a turn on signal, the applied sustainer voltage can be shifted in a manner to invert the state of all discharge sub sites. This inversion is reversible thus memory of the controlled state of a discharge site is not lost in an inversion and reinversion of the device. For example where a cell is off and it is desired to transfer it to an on state of dishcarge only in response to a coincidence of signals to all ofits conductor inputs, the device can be inverted by a shift in the sustainer level to place the cell in an on condition and the signals to its conductor inputs can be applied. If all such signals are turn 05 signals the cell will turn off in response to their coincidence. Upon reinversion of the device the cell will be in an on state of discharge. On the other hand, had their been no coincidence of turn off signals, the cell would have remained on and upon reinversion would have returned to its original off state of discharge.

Erasure of an on cell can be performed by imposing a coincidence of turn off signals on all of the cells sub sites while it is subject to a normal sustainer voltage and without resort to an electronic inversion of the device.

Particular utility is realized with the above features by employing a plurality of cells in a matrix. Grouped discharge sub sites or cells form individual display sites or image bits in such a matrix. The intercell spacing in the matrix is such that the discharge state of a sub site in one cell has no effect upon the discharge state of a sub site in another cell.

Where a matrix of multiple sub site cells is employed multiplexing can be performed within the device by interconnecting the sub sites of different cells to common turn off signal sources in arrangements such that each cell is controlled by a unique combination of signal sources. A particularly advantageous system employs only turn off or erase signal electronics in conjunction with sustainer shift inversion control for control of a display panel having a matrix of multiple sub site cells. Where the inversion and erase signal techniques are as disclosed in United States Patent Application Serial No. 372,553 filed herewith in the name of Jerry D. Schermerhorn entitled Method of Driving and Addressing Gas Discharge Panels by Inversion Techniques" (Case $42513) employing the circuits disclosed in United States Patent Application Serial No. 372,549 for Circuits for Driving and Addressing Gas Discharge Panels by Inversion Techniques by Jerry D. Schcrmerhorn, filed herewith, particular economies are realized since the turn off or erase signal sources can be normally open transistor switches, termed pulsers", which pull the sustainer developed voltages of conductors to ground or a slight offset from ground. These voltage levels enable control of both the p-n-p pull-up pulsers and the n-p-n pull-down pulsers from 'I'IL logic without special interface circuitry. Further as taught in these applications the same pulsers can be employed for write functions when applied to one conductor array and for erase functions when applied to the other conductor array by the use of diodes an coupling means to the display connector lines. When these economies are combined with those of the internal logic achieved by spa tial discharge transfer a very significant simplification of discharge device control is realized.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a gaseous discharge display/- memory panel operated according to this invention and comprised of a matrix of cells each having four discharge sub sites connected to diagrammatically illustrated sources of operating potentials and the controls therefor;

FIG. 2 is a cross-sectional view (enlarged but not to proportional scale since the thickness of the gas volume, dielectric layers and conductors have been enlarged for purposes of illustration) taken on the lines 22 of FIG. 1.

FIG. 3 is an enlarged plan view of the conductor cross points of one discharge cell made up of four discharge sub sites together with lines generally representing the discharge regions between individual cross points and the interconnecting fringe regions which give rise to spatial discharge transfer between grouped sub sites;

FIG. 4 is a diagrammatic plan view of a single cell comprising two discharge sub sites to illustrate the most elemental form of logic element operable according to this invention;

FIG. 5 illustrates in diagrammatic plan view a matrix of cells of the type shown in FIG. 4; and

FIG. 6 is a block diagram of the sustainer and pulser circuits coupled to a matrix of cells, shown in diagrammatic plan view, and illustrates multiplexed sub sites, conductors and pulsers which are operated by inversion and erase-to-write techniques to achieve internal panel logic by spatial discharge transfer.

DESCRIPTION OF THE PREFERRED EMBODIMENT One form of multicelled gas discharge display/memory device upon which the method of this invention is practiced when coupled to the control system of this invention, is shown in FIGS. 1 and 2. That device utilizes a pair of dielectric films 10 and 11 separated by a thin layer or volume of a gaseous discharge medium 12, the medium producing a copious supply of charges (ions and electrons). These charges are alternately collectible on the surfaces of the dielectric members at opposed or facing elemental or discrete areas defined by the conductor arrays on the non-gas contacting sides of the dielectric films l0 and 11. For convenience the upper array will be termed the x array and the lower array the y array. While the electrically operative structural members, such as the dielectric members 10 and 11 and the x and y conductors, are all relatively thin (being exaggerated in thickness in the drawings), they are formed on and supported by rigid non-conductive support members 13 and 14 respectively.

One or both of the non-conductive support members 13 and 14 pass light produced by discharges in the elemental gas volumes unless only the memory function is utilized, in which case they can be opaque. Advantageously they are transparent glass. Members 13 and 14 essentially define the over-all thickness and strength of the panel. They serve as heat sinks for heat generated by discharges and thus minimize the effect of temperature on operation of the device. For example, the gas layer 12 is usually under 10 mils and typically about 4 to 6 mils in thickness as determined by spacer l5. Dielectric layers 10 and 11 (over the conductors) are usually between I and 2 mils thick. Support members 13 and 14 are typically about Va to V4 inch thick.

Spacer 15 may be made of the same glass material as dielectric films 10 and 11 and may be an integral rib formed on one of the films 10 and 11 overlying dielectric members 13 and 14 or directly on the dielectric members 13 and 14 and fused to the other film or mem her to form a bakeable hermetic seal enclosing and confining ionizable gas volume 12.

Conductor arrays 16 and 17 may be formed in situ on support members 13 and 14, for example as individual conductor strips about 8,000 angstroms thick, and may be transparent, semi-transparent, or opague conductive material such as tin oxide, gold or aluminum. At least a pair of conductor strips is employed in at least one array, as disclosed in FIGS. 4 and 5, and where AND logic is to be accomplished in both conductor coordi* nates, a plurality of pairs of conductor strips are utilized in each array 16 and 17 as shown in FIGS. 1, 2, 3 and 6. Grouped cross points 18 of .r conductor strips 19 and y conductor strips 20 define discharge sub sites which are sufficiently close to each other as to have a discharge in one institute a discharge in the other. Thus, the combined sub sites are considered a cell 21. In order to disignate cells 21 in the illustrated othogonal mathrix, they will be assigned reference characters of their coordinate and rank or column as x-l through x-4 and y-l through y-4 in FIG. 1. Further, since a multiplicity of conductors can be present in a rank or column alphabetical suffixes will be applied. Thus the lower left-corner cell 21 of FIG. 1 is designated cell x-l, y-l and is made up of conductor strips 19-1a and 19-11), and 20-10 and 20-11). Similarly, the cross points 18 are designated by their conductor strips so the lower left cross point of cell x-l, y-l is l9-1a and 20-1a.

As described above the construction of the display device can assume many forms including equally spaced curved support surfaces for the conductor ar rays. A preferred form is a flat display panel made up of parallel dielectric support panels which can be transparent glass for display of the cells as discrete lighted spots in a matrix forming a darker background or of darkened spots on a lighted background. Generally, the device construction can be conventional and according to the open celled construction of Baker et al. U.S. Pat. NO. 3,499,167. Sustaining and discharge state parameters can also be according to Baker et al.

In the illustrated construction of paired, orthogonally related conductors a typical cell 21 is comprised of straight strips three mils wide spaced on six mil centers so that a three mil open strip is between each pair. The cells in such an array are typically spaced on sixteen mil centers in order to insure isolation of spatial discharge transfer to intracell discharge sub sites. It is to be appreciated that the interaction betwen sub sites is based on the fringing of the discharge efi'ects beyond the shadow area of the conductor cross points. Typically, a plane panel device having a neon-krypton or neonargon gas atmosphere with neon about 99.7% by weight at about atmospheric pressure and a thickness of 4.5 to 4.7 mils exhibits spatial discharge transfer between electrodes up to 3.5 to mils apart without interaction between elements 7 to 10 mils apart, depending to a degree on the size of the conductors, the thickness of the dielectric overcoat, and the gas parameters.

The spacing in an array of the grouped conductors having portions which constitute effective electrode areas of sub sites of a cell can be within a range which depends to a degree upon the thickness of the dielectric overcoat l0 and 11 above the conductors and the gas volume geometry, composition and pressure. In general the discharge characteristics of the gas are a determining factor. Discharges occur in the region of the gas volume which is proximate to the sub site electrodes of the opposed arrays with some extension beyond the projection of the areas perpendicular to the conductor arrays. Thus there is also a lower limit to the conductor spacing of grouped conductors of a cell in an array. When the conductor edges are too close, the field pattern of one can extend over the region of influence of others whereby an erase signal imposed on less than all sub sites of the cell draws enough charge from the walls of the sub site of the adjacent grouped conductors to place all sub sites of the cell in an off state. First and second paired conductors of one array such as 19-10 and l9-lb should be conductively isolated from each other, so spaced from each other and the sub site electrode areas of a conductor or conductors in the opposed array as to be adapted to initiate an on state of discharge in a discharge sub site including one of the first and second conductors which is in an 011' state of discharge in response to an on state of discharge in the discharge sub site of the other of the first and second conductors, and so spaced from each other and the sub site electrode areas of a conductor or conductors in the opposed array as to be adapted to maintain an on state of discharge in a discharge sub site including one of the first and second conductors in response to the transfer of the other sub site including the other of the first and second conductors from an on state of discharge to an off state of discharge in response to a manipulating sigrial superimposed on the sustainer voltage imposed on those conductors.

A sustainer voltage component which periodically shifts in level on a cyclic basis is applied to each of the x and y arrays to impose a composite sustainer voltage which alternates with a total excursion across the cells and each sub site of 2 V typically about 220 volts for the exemplary constructions. In order to manipulate the discharge state of the cells and sub sites, voltages are imposed on the sustainer level. By definition, for any given set of cell parameters the sustainer voltage 2 V, is such that a cell in the on state" of discharge is sustained in the on state as the voltage alternates by causing the wall charge accumulated on the dielectric surfaces to transfer to opposed surfaces and provide a wall voltage augmenting the next half sustainer cycle to fire the cell while a cell in the off state of discharge remains in that state during the alternation. Transfer of an off state site to an on state of discharge is accomplished by raising the applied voltage to a level which institutes a discharge, usually as a signal superimposed on and augmenting the sustaining voltage. In the process of initiating a discharge in one sub site the positive ions 24 in the gas 12 accumulate on the dielectric surface overlying the negative conductor in its region of registry with its opposed conductor region and the negative particles, electrons 25, accumulate on the dielectric overlying the positive conductor. These charged particles are excited in the gas volume between the electrodes subject to the firing voltage and while they are generally localized to that region some are in fringe areas beyond the zone in registry with the registering electrodes. Such fringing which may tend to follow the underlying conductors in the vicinity of the cell wall so that the region near the cell wall of the x array conductors is elongated in the x dimension, represented by the dashed line 22, while that near the y conductor wall is elongated in the y dimension, represented by the dotdashed line 23. Further, the fringing is sufficient so that sustainer voltage fields imposed on the adjacent sub sites of a cell having one sub site in an on state of discharge will attract sufficient charged particles into those sub sites to place them in an on state of discharge either in the same cycle of sustainer voltage in which the first sub site was turned on or the next succeeding cycle.

Since the spatial discharge transfer between sub sites is dependent upon the proximity of the sub sites, the sites themselves can be arranged in many desired forms as in the form of characters such as letters or numerals by parallel and closely spaced conductors in at least one array. Further, paired conductors in one array can cooperate with a single conductor in its opposed array as illustrated in FIGS. 4 and 5. The gating function of this form of device can be arranged with greater numbers of inputs by grouping a greater number of conductors in spatial discharge transfer proximity to each other as with three or more parallel conductors.

A convenient construction for devices of the type shown in FIGS. 1, 2 and 3 is to apply and secure conductors l9 and 20 in their support members 13 and 14. Their dielectric layers 10 and 11 are formed of an inorganic material, preferably in situ, as adherent films or coatings which are not chemically or physically affected by elevated temperatures. One such material is a solder glass such as Kimble SG-68 manufactured by and commercially available from the assignee of the present invention. The glass has a thermal expansion characteristic substantially matching the thermal expansion characteristics of certain soda-lime glasses suitable, when in plate form, for supporting members 13 and 14. Dielectric layers and 11 must be smooth and have a dielectric strength of about L000 volts per mil and be electrically homogenous on a microscopic scale (i.e. no cracks, bubbles, crystals, dirt, surface films or other irregularities). Also, the surfaces of dielectric layers 10 and 11 should be good photo-emitters of electrons to enable priming or conditioning of the cells for transfer to an on state of discharge. Alternatively, dielectric layers 10 and ll may be overcoated with materials designed to produce good electron emission, as in United States Letters Patent No. 3,634,719, issued to Roger E. Ernsthausen.

The ends of paired x array conductos 19-10, l9-lb, l9-na, l9-nb and support members 13 extend beyond the spacer side wall 15 enclosing gas volume 12 within the margin 26 and are exposed for the purpose of making electrical connection to external circuitry generically termed the interface, addressing and sustaining voltage circuits" 27. Likewise, the ends of paired y array conductors -la, 204b, 20-m1, 20-nb on support member 14 extend beyond spacer side wall 15 and are exposed for the purpose of making electrical connections to the circuits 27.

A partiicular advantage of the conductor configura tions of the illustrated devices is their capability to function as coincidence gates or logic ANDs by virtue of spatial discharge transfer. In some utilizations it is desirable that a cell change its discharge state only when a coincidence of input signals are imposed. Herctofore, such coincidences were utilized for control of a cell by circuitry external of the device. Since plural individual inputs for manipulating signals are available for at least one array of a cell according to this invention and the discharge sub sites of that cell have coupled operation in their transfer into the on state of dis charge, the transfer to the off state for the cell can be accomplished only if all of its discharge sub sites are in the off state of discharge simulataneously. The requisite coincident off state of all sub sites can be employed to either write or erase a cell. A cell in the on state of discharge can be erased by employing coincident erase manipulative signals addressed to all conductors of the arrays which have cross-points defining discharge sub sites of that cell while the device is operating in its normal mode. A cell in the off state of discharge can be written by inverting the discharge state of the matrix including the cell so that the subject cell is in an on state of discharge, then erasing that cell by applying erasing signals to all sub sites of the cell to place them all in an off state of discharge, and then reinverting the matrix so that the subject cell is in the on state.

Cells made up of sub sites grouped for spatial discharge transfer have logic OR functions whereby the initiation of an on state of discharge in any one sub site will institute an on state in the sub sites with which it is grouped. Resetting of a cell employed as an OR requires the coincident application of turn off signals to all sub sites of the cell. Such reset can be performed by coincident clocking of turn off signals at a convenient time preceding the utilization of the cell as an OR.

All cells of a display panel can be inverted in their discharge state by shifting voltage levels applied to the cells of the panel. For a given operating mode established by a given sustainer voltage applied as component voltages on the x and y arrays, all cells in the on state of discharge have a wall voltage on the dielectric film overlying the conductor portion defining the discrete discharge sub sites established at a level approaching the applied voltage. This wall charge voltage is opposite the polarity of the voltage applied to the underlying electrodes. Upon reversal of the polarity of the applied sustainer voltage. the wall charge voltage augments the sustainer voltage sufficiently to impose the firing voltage of the discharge sub sites across the ionizable gas in those sub sites. The discharges occur and the charge particles accumulate on the cell walls in an opposite orientation and corresponding wall voltage levels as for the preceding half cycle of the sustainer voltage so that upon the next reversal of the sustainer voltage the wall charge voltage again augments the voltage across the cell to achieve the firing voltage. Cells in the off state have an off state wall voltage, usually midway between the extremes of the excursions of the sustainer voltage.

Inversion of a cell matrix subject to a sustainer voltage is achieved by shifting the excursion limits of the sustainer while continuing to impose the sustainer voltage magnitude, 2 V across the conductor arrays forming the matrix. The shift is such that the off state wall voltage level for the shifted sustainer is at or near the on state wall voltage established prior to the shift and the on state wall voltage for the shifted substainer is at or near the off state wall voltage established prior to the shift. The shift will therefore cause the prior off state wall voltage level to augment the next sustainer voltage transition to the cell firing level and place the formally off cells in an on state while the wall voltage of the formerly on state cells is at the new off state level and has no augmenting effect so that the former on state cells are off while the inversion levels of sustainer voltage are imposed. Reinversion of the cell matrix is by a shift of sustainer voltage levels to their original levels. One form of a suitable sustaining voltage ciruit for cell matrix discharge state inversion is shown in the aforenoted Schermerhom patent application entitled Circuits for Driving and Addressing Gas Discharge Panels by Inversion Techniques.

Write or turn on" signals are applied to individual sub sites through pulsers which are synchronized with the sustainer voltages. A pulser, which can be in the form of a normally open switch, is actuated to superimpose a voltage augmenting the sustainer voltage sufficiently to fire the sub site and initiate a discharge in gas 12 between its conductors l9 and 20. Such pulsers are well known.

The erase signals, manipulative signals for individual discharge sites, are imposed in opposition to the currently applied sustainer voltage at a level sufficient to discharge the wall charge on the walls of the addressed cell which is in the on state" of discharge without accumulating a sufficient wall charge on the opposite wall to augment the next sustainer voltage transition to the site firing level. In the circuits of the patent application entitled Circuits for Driving and Addressing Gas Discharge Panels by lnversion Techniques" the erase signals for both the normal sustainer voltage operating mode and the inverting sustainer voltage operating mode are imposed by grounding the conductors of the opposed array which, by their cross point, define the addressed discharge site. Where the circuit of that disclosure applies the sustaining voltage components for the x array to all conductors of the x array, the panel of FIGS. 1, 2 and 3 has its cells controlled by erase signals applied coincidentally to the grouped conductors of each array the cross points of which constitute the discharge sub sites of the cell to be addressed. Thus for cell x-l, y-l conductors x-la and x-2a would receive x erase signals and conductors y-la and y-2a would receive y erase signals so that all of the discharge sub sites of cross points l9-1a, 20-1a and l9-la, 20-l19-1and 19-1b, 20- la and 19-h, 20-lb are transferred to the off state.

While cells 21 each composed of four discharge sub sites 18 have been shown as made up of a cross point of an a conductor of an a conductor set and a b conductor of a b conductor set for each of the x array 16 and the y array 17, it is to be understood that only two such proximate cross points are required to achieve discharge interaction of spatial discharge transfer. As shown in FIG. 4, logic can be accomplished internally with a single x conductor 28 and paired y conductors 29 and 31 having their cross points 32 and 33 with 28 sufficiently proximate for spatial discharge transfer. With a sustainer voltage imposed between 28 for the x component and 29 and 31 for the y component write partial select signals on 28 and either of 29 or 31 will institute a discharge at both discharge sub sites 32 and 33. Erase partial select signals, however, will not be effective to transfer the cell 34 comprising 32 and 33 to an off state unless applied to all conducting 28, 29 and 31.

FIG. shows a matrix 35 of cells 36 each of which comprises an x conductors 37-1 37-4 and one conductor of the a set of y conductors and one conductor of the b set ofy conductors 38-1 38-4 to make up a plurality of cells of two sub sites each.

The spatial discharge transfer function of gaseous discharge devices having proximate conductor portions which define interacting discharge sub sites lends itself to both positive and negative signal logic performed internally of the device. In this regard an OR function can be considered a coincidence gating of logic 0 signals and an AND function a coincidence gating of logic 1 signals. Alternatively the OR function is an anti coincidence gating function for logic 1 signals. Since the states of discharge of all sub sites of devices having proximate conductor portions can be inverted by a sustainer shift and since either write or erase functions can be performed in either or both states, i.e. the normal or inverted mode of operation, many logic combinations are available from a system including a device offering spatial discharge transfer, a sustainer voltage source, and a means to selectively transfer the state of discharge of a sub site.

A simple utilization of a device as an illuminated indicator in response to an internal OR function can comprise a single cell made up to two spatial discharge transfer related sub sites 32 and 33 as in FIG. 4 having a sustainer voltage source included in the interfacing, addressing and sustaining voltage circuits 27 and interface inputs to selection logic which actuates either of two turn on pulsers, all in circuits 27. Such an arrangement will turn on the cell in response to a turn on signal at either to two signal sources. The interface and selection logic will decode the signals and, depending upon which source imposes the signal, will actuate turn on pulsers coupled to lead 28 and one or the other of leads 29 and 31. Sub site 32 and 33 will thus have its sustainer voltage augmented by the partial select signals on 28 and 29 or 31 to impose a discharge firing level across gas 12. Thereafter the other sub site will be raised to its firing level and the cell 34 will be fully on.

Cell 34 can be individually actuated to provide an internal AND logic function for applications such as proposed above where the circuits 27 are arranged to precondition the cell to the on state of discharge and the signal responsive pulsers for the sub sites 32 and 33 issue erase signals in response to actuating signals at the user interface. Thus, in response to a signal at the user interface circuits 27 can be arranged to momentarily invert the cell. While such inversion will fire the cell the light emitted in the brief interval, e.g. one or two sustainer periods of twenty microseconds for a fifty kilohertz sustainer, the resultant light will not be effective as an indicator. During the inversion of the cell the applied signals can be sampled. If a coincidence is imposed so that pulsers to both sub sites 32 and 33 issue erase signals, the cell will be transferred to the off state during the inversion interval and upon reinversion, will be in an on state for the preponderant normal sustainer operating mode. Erasure of the cell where it is desired to extinguish the indicator can be accomplished by coincident operation of the erase pulsers while the cell is operated in the normal operating mode.

The selection logic can be expanded to accomodate a plurality of cells and selectively transfer their state of discharge when those cells are in a matrix as illustrated in FIGS. 1 and 5. Such matrices can be controlled by a greater number of inputs at the user interface and selection logic which selects the cell and identifies the discharge site conductors thereof which are to be pulsed. As in the single cell operations, control logic clocks the discharge state manipulating signals in proper sychronism with the sustainer pulsations for the write or erase functions required. A plurality of cells can be manipulated simultaneously in such a system provided however that such operation does not result in the manipulation of cells which are not to be altered. Where such undesirable operations might occur cells can be manipulated in sequence, as in successive sustainer voltage periods.

Although transfer to an on state of discharge has been suggested as the desired response of cells, it is to be appreciated that a transfer to an off state can also be employed either in a single cell operated as an individual element offering internal logic functions or in a matrix of cells each offering the internal logic functions. For example where an image is to be developed by means of a plurality of cells in a matrix the image can be either one or more darkened cells, cells in the off state in a lighted field, a field of cells in the on state or lighted Cells in a field of darkened cells. Thus if darkened cells in a bright field are desired, the matrix is not inverted following the application of coincident erase signals to the selected cells which are to be manipulated. The usual operation of lighted images on a darkened panel where internal AND logic is employed is achieved by applying a sustainer voltage to the matrix so that the field of cells is dark, shifting the sustainer level to invert the discharge state of the field of cells, applying erase signals to the sub site conductors selected by the selection logic so that those cells having all sub sites coincidently erased are extinguished and then reinverting the matrix by shifting the sustainer levels.

A more effective use of spatial discharge transfer internal logic in a gas discharge display/memory device is illustrated in FIG. 6. In this arrangement the array conductors are connected in parallel to erase pulsers so that actuation of any pulser can be effective on a plurality of sub sites. Each cell is arranged with its sub sites connected to a unique combination of pulsers. As noted in the case of the arrays of FIG. I, the conductors are in paired sets in each array. For purposes of illustration the conductor sets are shown connected to their pulsers from opposite side of the arrays. When any combination of an x array a set pulser, and x array h set pulser, a y array set pulser, and a y array b set pulser is energized a unique cell will be transferred from the on state of discharge to the off state. Details of the sustainer and erase pulser circuits are set forth in the aforenoted patent application entitled Circuits for Driving and Addressing Gas Discharge Panels by lnversion Techniques".

Control of the display panel 45 from a suitable signal source (not shown) is achieved through user interface 46. Signals from the interface, ordinarily in binary form, are passed to selection logic circuit 47 where they are decoded to address appropriate pulsers for the a and b conductors of the x and y arrays to erase the desired matrix cell. The decoded signals are applied in proper relationship to the sustainer voltage waveforms applied across the conductor arrays by control logic 48.

A sustainer waveform is applied across the .t array 49 and the y array 51 by means of pull up busses 52 and 53 and pull down busses 54 and 55 respectively. The sustainer is developed as assymetric componenets to facilitate electronic inversion and enable cell manipulation employing only erase pulsers. For example a component for the x array 49 can be in the form of periodic pulsations between a level V and V, developed respectively by a pull up circuit 56 connected to pull up buss 52, and a pull down circuit 57 connected to pull down buss 54 while a component for the y array 51 can be periodic pulsations between a level V and a reference level V which is advantageously at or near external ground, developed respectively in a pull up circuit 58 connected to pull up buss 53 and a pull to ground circuit 59 connected to pull down buss 55. These circuits are operated at regular intervals defined by the sustainer waveform period with a phase relationship such that the value (V V/.)+(V V(.-) equals 2 V, or a voltage across the arrays in the range required to maintain an on state discharge site on and an off state discharge site off in the absence of a manipulating signal. Control logic 48 supplies clocking signals to the sustainer circuits as be leads 61, 62, 63 and 64 to circuits 56, 57, 58 and 59 respectively.

If the above described waveform is considered the normal sustainer operating mode, the system can be shifted to an inverted operating mode by shifting the sustainer level so that the wall charge voltage of sites in an on state of discharge falls in the range of wall voltage of off state sites for the new sustainer level, and so that sites in an off state of discharge have a wall voltage which falls in the range of an on state wall voltages for sites in the off state of discharge for the new level. This new level can be achieved by interchanging the sustainer components applied to the arrays so that the x array component has excursions between V and V while the y array component has excursions between V and V Such an interchange can be accomplished by the control logic 48 clocking the pull up circuit 56 and a pull to ground circuit 65 for the x array busses 52 and 54 and by clocking the pull up circuit 58 and a pull down circuit 66 which pulls buss 55 to V for the y Clocking signals are passed from 48 over leads 67 and 68 to circuits 65 and 66 respectively. The inversion and reinversion operations of these sustainer circuits is discussed in greater detail in the patent application Circuits for Driving and Addressing Gas Discharge Panels by Inversion Techniques". For illustrative purposes the voltages V and Vy can be about 1 l0 volts and V and V can be about 70 volts. V and V can be about 1.0 volt.

The sustainer components components are applied to the arrays through diodes and enable the conductors which isolate the conductors of the arrays and enable the conductors to hold their voltages capacitively until pulled to a new level by a sustainer transition or an address pulser. Pull up buss 52 is coupled through isolation diodes 71 poled to pass current from the busses to display connecter lines 72, 73, 74, 75, 76 and 77 with lines 72, 73, and 74 coupled to the a set of .r conductors and lines 75, 76 and 77 coupled to the b set of x conductors. When sustainer pull up circuit is on it applies V to all of lines 72 through 77 to raise all x conductors to V ln similar fashion pull up buss 53 couples sustainer pull up circuit to the y array conductors to impose V on those conductors. Isolation diodes 78 are poled to pass current to the display connector lines 81, 82, 83 for the a set ofy conductors and lines 84, 85 and 86 for the b set of y conductors.

The x array pull down circuits 57 and 65 are coupled through buss 54 and diodes 87 to display connector lines 72 through 77. Buss 55 for the y array connects pull down circuits 66 and 59 to display connector lines 81 through 86 by diodes 88. Diodes 87 and 88 are poled to pass current from the conductors to the buss.

Manipulation of the discharge state of the discharge sites is by pull down pulsers 91 through 96 and pull up pulsers 101 through 106. Each of these pulsers is controlled from the user interface 46 and selection logic 47 through the control logic 48 in coordination with the clocking and inversion producing level shifts of the sustainer. Signals actuating the pulsers are passed on leads 111 through 116 from control logic 48 to pulsers 91 through 96 respectively and on leads 121 through 126 to pulsers 101 through 106 respectively. The pulsers each pull to voltage V the conductors of the arrays to which they are connected through their respective display connector lines. Thus pull down pulsers 91 through 96 pull array conductors which are at a voltage higher than V those at V by virtue of sustainer pull up circuit 56 for an x conductor or 58 for a y conductor. [t is to be appreciated that the pull up and pull down pulsers need not pull to identical voltages in order to impose effective partial select signals on the discharge sites. For example the pull up pulsers can pull to a level V which is somewhat different than the level V to which the pull down pulsers pull their conductors.

Pull down pulsers can be n-p-n transistors functioning as normally open switches between their emitters at V and their collectors connected to the pulser outputs. These switches are closed to apply V to their outputs when their base electrodes receive an actuating signal from control logic 48. Output leads 131 through 136 of pull down pulsers 91 through 96 are coupled to a display connector line of each array with pulsers 91, 92 and 93 connected to the a conductors and pulsers 94, 95 and 96 connected to the b conductors. Steering diodes 137 for the xa display connector lines 72, 73 and 74 and 138 for the xb display connector 75, 76 and 77 are poled to pass the pull down pulser signals to the .r array when the x sustainer component is high. Steering diodes 139 for the ya display connector lines 81, 82 and 83 and 140 for the yb display connector lines 84, 85 and 86 are poled to pass the pull down pulser signals to the y array when the y sustainer component is high. Since the pulsers are clocked only when the sustainer components on the opposed arrays are at levels on opposite sides of V the signals are effective on only one array at any instant.

Pull up pulsers 101 through 106 are p-n-p transistors having their emitters connected to V and their collectors connected to output leads 141 through 146 respec tively. They funciton as normally open switches until actuated through selected input leads 121 through 126 to their base electrodes. When turned on, they pull up their display connector line which is low without effect on their display connector line which is high by virtue of steering diodes 147 to the xa display connector lines 72, 73 and 74, 148 to the .rb display connector lines 75, 76 and 77, 149 to the ya display connector lines 81, 82 and 83 and 150 to the yb display connector lines 84, 85 and 86.

The effect of interconnecting the conductors in each array in sets enables a unique combination of an xa, .rb, ya and yb pulser to be established for each cell in the matrix of cells of the panel. If the array conductors are assigned numbers lxa through 9xa, lxb through 9xb, lya through 9ya and lyb through 9yb and are connected with the xa and ya conductors of three adjacent paired conductors in parallel and the xb and yb conduc tors of every third conductor pair in parallel, six pulsers are employed to uniquely select nine lines in each axis and twelve pulsers select 8| unique cell sites. Where a nine bit binary input provides 512 distinct signals and that number of lines are provided in a coordinate of a display panel, the two set system employing two conductors per line conveniently decodes with 32 pulsers each connected through display connector lines to 16 panel conducotr for one set and with 16 pulsers each connected to 32 panel conductors for the other.

The number of pulsers and paralleled conductors required to produce a given number of unique conductor pairs can be reduced further where all possible combinations of the conductors in an array are utilized. Effectively in the illustrated structure each of the three pulsers for the a set of conductors should have their conductors uniquely paired and each of the conductors in the b set should similarly be combined. If there are M coordinate locations in the x dimension and N,, coordinate locations in the y dimension in the display and double conductors are employed for each location, there will be 2 N ,x conductors and 2N y conductors in the display/memory panel grouped in pairs for each axis. With 11 voltage pulse sources per axis, the maximum number of lines L per axis which can be uniquely selected is n (n-l )/2 L, i.e the number of combinations of n things taken two at a time. In FIG. 6 n is six and unique pairs of conductors could have been illustrated as lines in both the x and y axes, had all possible pairings been employed and has space permitted. This would have afforded 225 unique cells in the matrix addressed by 12 pulsers. Where 512 unique paired eonductor lines were desired the minimum number of pulsers and display connector lines to the array is 33. It should be noted that these reductions in the number of pulsers lead to more complex encoding and decoding for addressing purposes.

In actuating xa, xb, ya and yb pulsers for a unique four discharge sub site cell of the matrix a number of cell sub sites will be subject to the erase signals without altering the state of a cell in the on state since at least one of their sub sites will not be erased and will reignite the entire cell in the next half sustainer cycle. Thus there will be some coordinate locations which have one, two and three sub sites of the four that could be erased or transferred to an off state of discharge, leaving at least one which is not and is effective as a control sub site to reignite to the on state those which were erased, As described above, where this writing of a unique cell by addressing the matrix through the pulsers for the four conductors unique to the cell is practiced in a normally off field of cells, the matrix of cells is inverted to place the field of off cells in an on state, the addressed cell is erased, and the matrix is reinverted so that the addressed cell is in an on state with the other originally off cells returned to their off state.

It is to be recognized that the number of conductors over each coordinate location of an array can be more than two and need not be equal in each array. That is there could be three or more conductors having portions so proximate each other and at least one conductor in the opposed array that spatial discharge transfer is realized between the sub sites defined by each pair of proximate conductor portions in opposed arrays. For example each cell can be formed with an .r array conductor portion and three or more y array conductor portions, or each cell can be formed with three or more proximate conductor portions in each array.

The combinations of discharge sub sites to achieve spatial discharge transfer can be with a single conduc tor in one array and grouped conductors in the other array as where the discharge cells are in alignment along the single conductor as paired sub sites where the second array has paired proximate conductor portions as the conductor groupings. More commonly the cells are in a matrix having width and length where plural conductors are in each array. Again while only one array need have grouped conductors forming proximate conductor portions for spatial discharge transfer within the cell it is advantageous to have both arrays so arranged. Each conductor can have a plurality of regions spaced along its length in its array providing proximate conductor portions forming the electrodes of discharge sub sites. Cell electrodes or proximate conductor portions can be connected in electrical parallel as well as series connection in the cross point or grip matrices shown and maintain unique discharge sub site combinations for individual cell control where erase writing techniques are utilized.

Since coincident erasure of all sub sites of a cell is necessary to erase a cell, unique writing of a cell is accomplished by inverting the discharge state of the matrix, as by actuating control logic 48 to interchange the sustainer component waveforms applied to the x and y arrays of conductors to shift the resultant sustainer level to turn on those cells normally off without loss of memory of previously written cells since they are turned off by the inversion. The coincident erase signals are then applied to the selected cell as determined by selection logic 47 and synchronized with sustainer voltage transitions in control logic 48 to activate the two pull up pulsers for the two conductors of the cell for the array at a low potential, V in the illustration, and the two pull down pulsers for the two conductors of the cell for the array at the high potential V whereby all four sub sites of the selected cell are erased. As noted above other sub sites made up from portions of the conductors of the erased cell sub sites will also be erased by these functions however since an on memory is retained in those other cells by the retention of at least one sub site in an on state those cells will be reignited in the next half sustainer cycle. Reinversion of the matrix places the newly erase written cell in an on state and returns any previously written cells to an on state while returning the background cells to an off state.

It is to be understood that the invention lends itself to many variations. For example inversion of discharge states can be accomplished with other than interchanged assymetric sustainer components. Logic with OR functions employing a selective turn on of one or more but less than all sub sites through the selection logic 47 and control logic 48 can be practiced on individual or groups of cells. Inversion techniques can be applied to OR functions in NOR logic operations. AND and NAND logic is realized with coincident erasure of all sub sites of a cell again with or without inversion of the matrix. Accordingly the above disclosure is to be read as illustrative and not in a limiting sense.

What is claimed is:

l. The method of perfoming logic functions internally of a gas discharge display/memory device having plural discharge sub sites each comprising a conductor of a first conductor array having a portion proximate to a portion of a conductor of a second conductor array, a volume of ionizable gas in the vicinity of the proximate conductor portions and a dielectric layer between at least one conductor portion and the gas, a plurality of the sub sites being grouped in a physical arrangement as a discharge cell with a spacing within a range of mutual influence such that an on state of discharge in one sub site of the cell institutes an on state of discharge in the remaining sub sites of the cell when subjected to a sustaining voltage waveform, comprising the steps of: applying a sustaining voltage waveform across the first and second conductor arrays; and applying a turn on signal to a sub site of said cell during the continued application of the sustainer voltage whereby an on state of discharge is instituted in the remaining sub sites of the cell.

2. The method according to claim 1 including the step, following application of the turn on signal, of applying coincident turn off signals to all discharge sub sites of the cell during the continued application of a sustainer voltage whereby the cell is transfer to an off state of discharge.

3. The method according to claim 1 wherein said turn on signal is applied by inverting the discharge state of all sub sites of said cell from an off state of discharge to an on state of discharge.

4. The method according to claim 3 whererin the sustainer voltage waveform is shifted to a level at which the wall voltage on the dielectric layer of an off state sub site augments the shifted sustainer voltage to impose an on state voltage across the discharge sub site.

5. The method according to claim 4 including the step, following the sustainer shift, of applying coincident turn off signals to all discharge sub sites of the cell during the continued application of a sustainer voltage, whereby the cell is transferred to an off state discharge.

6. The method according to claim 5 including the step, following the transfer of the cell to an off state, of shifting the sustainer voltage waveform to a level at which the wall voltage on the dielectric layer of an off state sub site augments the shifted sustainer voltage to impose an on state voltage across the discharge sub site.

7. The method according to claim 1 wherein the device includes a plurality of discharge cells each comprising grouped discharge sub sites with the intracell spacing of grouped sub sites being such that an on state of discharge in one sub site of a cell institutes an on state of discharge in the remaining sub sites of that cell when subjected to a sustaining voltage waveform, and the intercell spacing being such that the state of discharge in the sub sites of each cell is independent of the state of discharge in the sub sites of other cells, wherein the step of applying a turn on signal is selectively applied to a sub site of a cell selected to be transferred to an on state of discharge.

8. The method according to claim 7 including the step, following application of the turn on signal, of selectively applying coincident turn off signals to all dis charge sub sites of the cell transferred to an on state during the continued application of a sustainer voltage whereby the selected cell is transferred to an off state of discharge.

9. The method according to claim 7 including the step of inverting the discharge state of all sub sites of the plurality of cells by shifting the sustainer voltage waveform to a level at which the wall voltage on the dielectric layer of an off state sub site augments the shifted sustainer voltage to impose an on state voltage across said discharge sub site and the wall voltage on the dielectric layer of an on state sub site is at a level which does not augment the shifted sustainer voltage sufficiently to impose an on state voltage across said discharge sub site.

10. The method according to claim 1 wherein the device includes a plurality of discharge cells each comprising grouped discharge sub sites with the intracell spacing of grouped sub sites being such that an on state of discharge in one sub site of a cell institutes an on state of discharge sites of that cell when subjected to a sustaining voltage waveform, and the intercell spacing being such that the sub sites of each cell is independent of the state of discharge in the sub sites of the other cells, wherein the step of applying a turn on signal is by inverting the discharge state of all sub sites of the plurality of cells by shifting the sustainer voltage waveform to a level at which the wall voltage on the dielectric layer of an off state sub site augments the shifted sustainer voltage to impose an on state voltage across said sub site, including the step following the shift of sustainer voltage, of applying coincident turn off signals to all discharge sub sites of a selected cell during the continued application of a sustainer voltage whereby the selected cell is transferred to an off state of discharge.

11. The method according to claim 10 including the step, following the transfer of a selected cell to an off state of discharge, of shifting the sustainer voltage waveform to a level at which the wall voltage on the dielectric layer of an off state sub site augments the shifted sustainer voltage to impose an on state voltage across said sub site and the wall voltage on the dielectric layer of an on state sub site is at a level which does not augment the shifted sustainer voltage sufficiently to impose an on state volage across said discharge sub site.

12. The method according to claim 1 wherein the device includes a plurality of discharge cells each comprising grouped discharge sub sites with the intracell spacing of grouped sub sites being such that an on state of discharge in one sub site of a cell institutes an on state of discharge in the remaining sub sites of that cell when subjected to a sustaining voltage waveform, and the intercell spacing being such that the state of discharge in the sub sites of each cell is independent of the state of discharge in the sub sites of other cells, wherein the step of applying a turn on signal is applied to at least one sub site of each of a plurality of cells and including, electrically interconnecting a sub site of each of a plurality of cells which have sub sites which are not electrically connected, and, following the application of a turn on signal to a sub site of each of a plurality of cells each having at least on sub site interconnected with another sub site of said plurality of cells, applying a turn off signal to all sub sites of a selected cell of said plurality of cells each having at least one sub site interconnected with another sub site of said plurality of cells, whereby only said selected cell is transferred to an off state of discharge.

13. The method according to claim 12] wherein said turn off signal is applied to all sub sites of a selected plurality of cells of said plurality of cells whereby only said selected plurality of cells are transferred to an off state of discharge.

14. The method according to claim 12 including the step of turning on cells by shifting the sustainer voltage waveform to a level at which the wall voltage on the dielectric layer of an off state sub site augments the shifted sustainer voltage to impose an on state voltage across said discharge sub site and the wall voltage on the dielectric layer of an on state sub site is at a level which does not augment the shifted sustainer voltage sufficiently to impose an on state voltage across said discharge sub site.

15. The method according to claim 14 wherein the step of turning on cells is performed both before and after said application of a turn off signal.

16. The method according to claim 1 wherein said turn on signal to a sub site is a voltage pulse augmenting said sustainer voltage applied to the conductors of the first and second arrays whose proximate portions are elements of said discharge sub site.

17. The method according to claim 2 wherein said turn off signals are voltage pulses in opposition to said sustainer voltage applied to the conductors of the first and second arrays whose proximate portions are elements of all discharge sub sites of the cell.

18. The method according to claim 7 wherein said turn on signal to a sub site is a voltage pulse augmenting said sustainer voltage applied to the conductors of the first and second arrays whose proximate portions are elements of said discharge sub site.

19. The method according to claim 8 wherein said turn off signals are voltage pulses in opposition to said sustainer voltage applied to the conductors of the first and second arrays whose proximate portions are elements of all discharge sub sites of the cell.

20. The method according to claim 10 wherein said turn off signals are voltage pulses in opposition to said sustainer voltage applied to the conductors of the first and second arrays whose proximate portions are elements of all discharge sub sites of the cell.

21. The method according to claim 12 wherein said turn on signal to a sub site is a voltage pulse augmenting said sustainer voltage applied to the conductors of the first and second arrays whose proximate portions are elements of said discharge sub site.

22. The method according to claim 12 wherein said turn off signals are voltage pulses in opposition to said sustainer voltage applied to the conductors of the first and second arrays whose proximate portions are elements of all discharge sub sites of the cell.

23. The method according to claim 1 wherein the device includes a plurality of discharge cells arranged in a matrix with each cell comprising grouped discharge sub sites, each of a plurality of sub sites having a conductor comprising the proximate conductor portion thereof in one array which includes the proximate conductor portion of at least one other sub site, the device matrix having proximate conductor portions of grouped sub sites of cells in said one array and having intracell spacing of grouped sub sites such that an on state of discharge in one sub site of a cell institutes an on state of discharge in the remaining sub sites of that cell when the arrays are subjected to a sustaining voltage waveform, the device matrix having intercell spacing such that the state of discharge in the sub sites of each cell is independent of the state of discharge in the sub sites of other cells, including the step of connecting conductors of said one array in electrical parallel with other conductors in said array to a common discharge state manipulating signal source uniquely combined with another conductor in said array to form sub sites grouped as cells by connecting another discharge state manipulating signal source so that each signal source combination through combined conductors is unique; wherein the step of applying a turn on signal is applied to at least one sub site of each of a plurality of cells; and, following the application of a turn on signal to a sub site of each of a plurality of cells, applying a turn off signal to all sub sites of a selected cell of said plurality of cells.

24. The method according to claim 23 wherein the step of connecting conductors in electrical parallel is practiced on each conductor of said one array.

25. The method according to claim 23 wherein the step of connecting conductors in electrical parallel is practiced on a first and second set of conductors to connect one conductor of each of a plurality of sub sites in the first set and the other conductor of each of said plurality of sub sites in a second set.

26. The method according to claim 23 wherein each of a plurality of sub sites have a conductor comprising the proximate conductor portion thereof in each of said first and second conductor arrays which includes the proximate conductor portion of at least one other sub site and wherein the step of connecting conductors is practiced in said first and second arrays to connect conductors of an array in electrical parallel with other conductors in said array to a common discharge state manipulating signal source with each conductor uniquely combined with another conductor in said array to form sub sites grouped as cells by connecting another discharge state manipulating signal source so that each signal source combination through combined conductors is unique.

27. A system for performing logic functions internally of a gas discharge display/memory device having plural discharge sub sites each comprising a conductor of a first conductor array having a portion proximate to a portion of a conductor of a second conductor array, a volume of ionizable gas in the vicinity of said proximate conductor portions and a dielectric layer between at least one conductor portion and said gas; a plurality of said sub sites being grouped in a physical arrangement as a discharge cell with a spacing between sub sites within a range of mutual influence such that an on state of discharge in one sub site of said cell institutes an on state of discharge in the remaining sub sites of the cell when subjected to a sustaining voltage waveform; means to apply a sustaining voltage waveform across the first and second conductor arrays; means to shift the level of the sustaining voltage waveform to a level at which the wall voltage on the dielectric layer of a sub site in the off state of discharge augments the shifted sustainer voltage to impose an on state voltage across the discharge sub site connected across said first and second conductor arrays and the wall voltage on the dielectric layer of an on state sub site is at a level which does not augment the shifted sustainer voltage suffi ciently to impose an on state voltage across said discharge sub site; erase signals issuing means individual to each conductor of each sub site of said cell; and addressing means for selectively actuating said erase signal issuing means in coordination with operation of said means to apply and means to shift the sustaining voltage.

28. A system according to claim 27 wherein said erase signal issuing means are pull up pulsers and pull down pulsers; and including means coupling said pull up pulser signals to conductors having a relatively low voltage; and means coupling said pull down pulser signals to conductors having a relatively high voltage.

29. A system according to claim 28 wherein said coupling means for pull up pulser signals are unidirectionally conductive means individually connected between said pulser and a respective conductor of said first and second arrays each poled to pass signals from said pulser to a respective conductor at a lower voltage than said pulser signal; and wherein said coupling means for pull down pulser signals are unidirectionally conductive means individually connected between said pulser and a respective conductor of said first and second arrays, each poled to pass signals from a respective conductor at a higher voltage than said pulser signal to said pulser.

30. A system according to claim 27 including a plurality of cells each comprising a plurality of sub sites grouped as a cell, said cells being spaced such that the state of discharge in the sub sites of each cell is independent of the state of discharge in the sub sites of other cells.

31. A system according to claim 30 wherein individual sub sites of a plurality of cells have their conductor portions of said first and second arrays respectively interconnected to a common one of said erase signal issuing means, each of said cells having their sub site conductor portions connected to a unique combination of erase signal issuing means whereby only cells having all of their erase signal issuing means actuated in coinci dence are transferred from an on state of discharge to an off state of discharge.

32. A system according to claim 31 wherein said addressing means includes means to selectively actuate said erase signal issuing means to said conductor portions when said sustaining voltage is at said shifted level and when said sustaining voltage is at the unshifted level whereby a cell can be shifted selectively by erase signals between an on state of discharge and an off state of discharge.

33. A system according to claim 27 wherein said device has a plurality of discharge cells arranged in a matrix with each cell comprising a group of said discharge sub sites, each of a plurality of said sub sites having a conductor comprising the proximate conductor portion thereof in one array which includes the proximate conductor portion of at least one other sub site; said dis charge sub sites of each of said groups comprising a cell having proximate conductor portions in siad one array and being so spaced that an on state of discharge in one sub site of a cell institutes an on state of discharge in the remaining sub sites of that cell when the arrays are subjected to a sustaining voltage waveform; said cells being so spaced in said matrix that the state of discharge in the sub sites of each cell is independent of the state of discharge in the sub sites of other cells; means connecting conductors of said one array in electrical parallel with other conductors in said array with each parallel connected conductor uniquely combined with another conductor in said array to form sub sites grouped as cells; and wherein said erase signal issuing means are connected to said parallel connected conductors and to conductors combined therewith in cells whereby said erase signal issuing means are combined in unique combinations for each cell in said matrix.

34. A system according to claim 33 wherein said connecting means connects conductors in a first group of sets and a second group of sets; and wherein each cell has a conductor from the first group of sets and a conductor from the second group of sets.

35. A system according to claim 33 wherein said sub sites have a conductor comprising the proximate conductor portion thereof in the second array other than said one array which includes the proximate conductor portion of at least one other sub site; said second array including proximate conductor portions of sub sites grouped as cells; means connecting conductors of said second array in electrical parallel with other conductors in said second array with each parallel connected conductor uniquely combined with another conductor in said array to form sub sites grouped as cells, and wherein said erase signal issuing means are connected to said parallel connected conductors and to conductors combined therewith in cells respectively for each of said first and second arrays whereby said erase signal issuing means are combined in unique combinations for each cell in said matrix.

36. A system for performing logic functions internally of a gas discharge display/memory device having plural spatial discharge related discharge sites in a physical arrangement including a control discharge site and a controlled discharge site, each said site comprising a conductor of a first conductor array having a portion proximate to a portion of a conductor of a second conductor array, a volume of ionizable gas in the vicinity of said proximate conductor portions and a dielectric layer at least one conductor portion and said gas; said controlled discharge site being in discharge transfer proximity to said control discharge site; means to apply a sustainer voltage across the conductors of said control discharge site; means to apply a sustainer voltage across the conductors of said controlled discharge site; means to initiate an on state of discharge in said control discharge site; and control means to coincidently actuate said control and controlled discharge site respective sustainer voltage applying means while said control discharge site is in an on state of discharge an off state of discharge.

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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4045790 *Aug 22, 1975Aug 30, 1977Owens-Illinois, Inc.Matrix discharge logic display system
US4099097 *Jul 2, 1976Jul 4, 1978Owens-Illinois, Inc.Driving and addressing circuitry for gas discharge display/memory panels
US4100535 *Nov 2, 1976Jul 11, 1978University Of Illinois FoundationMethod and apparatus for addressing and sustaining gas discharge panels
US4105930 *Jul 19, 1976Aug 8, 1978Ncr CorporationLoad and hold means for plasma display devices
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Classifications
U.S. Classification365/116, 345/62, 345/68
International ClassificationG09G3/28, H03K19/02, G09G3/288
Cooperative ClassificationG09G3/297, G09G3/2922, G09G2320/0228, G09G3/296
European ClassificationG09G3/292E, G09G3/296, G09G3/297
Legal Events
DateCodeEventDescription
Jun 9, 1987ASAssignment
Owner name: OWENS-ILLINOIS TELEVISION PRODUCTS INC., SEAGATE,
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:OWENS-ILLINOIS, INC., A CORP. OF OHIO;REEL/FRAME:004772/0648
Effective date: 19870323
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:OWENS-ILLINOIS, INC., A CORP. OF OHIO;REEL/FRAME:004772/0648
Owner name: OWENS-ILLINOIS TELEVISION PRODUCTS INC.,OHIO